Most security bars, such as those used in prisons, banks, vaults, jewelry stores, museums and other barred windows, comprise a solid bar made of an appropriately strong metal such as iron or steel. Most typically, the biggest threat to the breach of security of a security bar is a hacksaw or similar tool, which is used to cut completely through the security bar, thereby rendering it useless.
In co-pending U.S. patent application Ser. No. 10/745,884, “Security Bar With Multiple Internal Rolling Bars And Electronic Monitoring,” filed on Dec. 26, 2003 by John A. Meyer (the inventor of the present invention) and commonly assigned to the assignee of the present invention, a security bar providing improved security from breach using a plurality of free rolling inner bars was described. In addition, U.S. patent application Ser. No. 10/745,884 also taught a method for electronically monitoring such security bars with the use of electrically conducting wiring. Specifically, such electrically conducting wiring could be advantageously connected into an electronic circuit such that the breach of the security bar—for example, as a result of a successful attempt to cut through the bar—resulted in a breach of the electrical conductivity of the wiring in the security bar. This breach would then be electronically detectable by the electronic circuit, thereby alerting appropriate authorities to the breach of the security bar. U.S. patent application Ser. No. 10/745,884 is hereby incorporated by reference as if fully set forth herein.
Despite the clear advantages of providing electronic monitoring of a security bar in the manner taught in U.S. patent application Ser. No. 10/745,884, such an approach does have some limitations. First, it is possible for someone attempting to breach the security bar (e.g., a thief or prison break accomplice) to create an electrical “short circuit” around the bar prior to cutting through it, thereby rendering the electrical conductivity within the security bar irrelevant to the overall electrical monitoring circuitry. In addition, even though such security bars are typically quite strong, any electrical conductivity within the security bar will most likely not be disturbed by merely deforming (i.e., bending) the bar—as opposed to breaking or cutting through it—thereby leaving the bar susceptible to such a breach by deformation.
Therefore, it would be highly desirable to provide a security bar which eliminates these limitations of the security bar of U.S. patent application Ser. No. 10/745,884, and which provides a more robust and secure monitoring against possible breach thereof.